If you have an Amazon.com Rewards Visa card, now might be the time to go shopping - they're currently offering 20% off purchases of a large list of "select" electronics, with a maximum total discount of $50. There is no maximum number of items you may use the discount on, but you can only use it on a single Amazon order - then it's gone. The promo code is TCH20ARC.
Some of the items up for grabs include the popular Chromecast, which you can snag for just $23.99 (plus tax, if applicable) right now. Fitbit, Jawbone Up, Dropcam, GoPro cameras, Philips Hue bulbs, Pebble smartwatches, Rokus, SSDs, Parrot AR.drones, and more are also in there. Basically, lots and lots of really cool stuff.
The catch, again, is that the purchase must be made with your Amazon Rewards Visa, the items must be from the list of select products, and you must reside in the US. So, have at it - it's unclear when this promotion ends (it's been going a couple weeks now), so take advantage while you can.